1. Field of the Invention
The invention concerns a vehicle headlight system with a light source and at least one reflector for forming the light emitted by the light source into a high beam and a low beam, and with a first shield adjustable between a position blocking the light of the light source over a maximal cross section and a position substantially allowing passage of this light via an actuating element.
2. Related Art of the Invention
A vehicle headlight system of this type is known from FR-A 2 657 681 and EP 0 863 047 B1.
These known headlight systems respectively use gas discharge lamps as light sources. In contrast to the double filament headlights previously employed for production of high and low beam lights in motor vehicles, gas discharge lamps in general have only a single cohesive light emission zone, so that a switching between high beam and low beam by change of the beam path in the headlight system is not possible. Both known headlight systems envision two discrete operating conditions, in which the part of the light emitted by the light source which forms the high beam is either transmitted or shielded in that the shield is adjusted to a position in which the light of the light source is essentially transmitted or, as the case may be, the light is blocked over its maximal cross section.
Since gas discharge lamps provide a substantially more glaring light than conventional incandescent filament lamps, a beam projection range regulation is mandated for headlight systems which have such discharge lamps, in order to prevent that, when a vehicle pitches while accelerating or changes the orientation of its body due to a load in the trunk, it produces an upward directed high beam which could blind oncoming traffic. One such beam range or amplitude control is conventionally accomplished in that the reflector of the headlight is mounted pitch-movable and is so controlled by an actuating element that the beam axis of the headlight maintains its orientation in space independent of the pitch of the vehicle. A light with a control of this type makes the headlight system comparatively bulky and expensive, since a frame or mounting must be provided about the respective reflectors, within which the reflectors are pivotably mounted, and that an actuating element must be incorporated to be effective between frame and chassis.
It is the task of the invention to provide a vehicle headlight system which, with simple and precise means, makes possible both a switching between high and low beam as well as allows the projection range of the low beam to be controlled. That means, while in the above described vehicle headlight systems there are provided only two positions of the first shield, the inventive system is allotted at least three such positions or settings, preferably an entire continuum of such positions, in which the shield can be brought.
In contrast to the above mentioned headlight systems, it is possible with the inventive system, when mounted in a vehicle, to produce not only the maximal blocking position, which represents the production of the low beam in a resting unloaded vehicle, but rather to also produce one of the intermediate positions.